Cypress CY7C1294DV18 User Manual

Mbit qdr- ii™ sram 2-word burst architecture

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9-Mbit QDR- II™ SRAM 2-Word

Burst Architecture

CY7C1292DV18
CY7C1294DV18

Cypress Semiconductor Corporation

198 Champion Court

San Jose

,

CA 95134-1709

408-943-2600

Document #: 001-00350 Rev. *A

Revised July 20, 2006

Features

• Separate Independent Read and Write data ports

— Supports concurrent transactions

• 250-MHz clock for high bandwidth
• 2-Word Burst on all accesses
• Double Data Rate (DDR) interfaces on both Read and

Write ports (data transferred at 500 MHz) @ 250 MHz

• Two input clocks (K and K) for precise DDR timing

— SRAM uses rising edges only

• Two input clocks for output data (C and C) to minimize

clock-skew and flight-time mismatches

• Echo clocks (CQ and CQ) simplify data capture in

high-speed systems

• Single multiplexed address input bus latches address

inputs for both Read and Write ports

• Separate Port Selects for depth expansion

• Synchronous internally self-timed writes

• Available in x 18 and x 36 configurations

• Full data coherency, providing most current data

• Core V

DD

= 1.8V (±0.1V); I/O V

DDQ

= 1.4V to V

DD

• Available in 165-ball FBGA package (13 x 15 x 1.4 mm)
• Offered in both lead-free and non-lead free packages

• Variable drive HSTL output buffers

• JTAG 1149.1 compatible test access port

• Delay Lock Loop (DLL) for accurate data placement

Configurations

CY7C1292DV18 – 512K x 18
CY7C1294DV18 – 256K x 36

Functional Description

The CY7C1292DV18 and CY7C1294DV18 are 1.8V
Synchronous Pipelined SRAMs, equipped with QDR™-II
architecture. QDR-II architecture consists of two separate
ports to access the memory array. The Read port has
dedicated Data Outputs to support Read operations and the
Write Port has dedicated Data Inputs to support Write opera-
tions. QDR-II architecture has separate data inputs and data
outputs to completely eliminate the need to “turn-around” the
data bus required with common I/O devices. Access to each
port is accomplished through a common address bus. The
Read address is latched on the rising edge of the K clock and
the Write address is latched on the rising edge of the K clock.
Accesses to the QDR-II Read and Write ports are completely
independent of one another. In order to maximize data
throughput, both Read and Write ports are equipped with
Double Data Rate (DDR) interfaces. Each address location is
associated with two 18-bit words (CY7C1292DV18) or 36-bit
words (CY7C1294DV18) that burst sequentially into or out of
the device. Since data can be transferred into and out of the
device on every rising edge of both input clocks (K and K and
C and C), memory bandwidth is maximized while simplifying
system design by eliminating bus “turn-arounds.”

Depth expansion is accomplished with Port Selects for each
port. Port selects allow each port to operate independently.

All synchronous inputs pass through input registers controlled
by the K or K input clocks. All data outputs pass through output
registers controlled by the C or C (or K or K in a single clock
domain) input clocks. Writes are conducted with on-chip
synchronous self-timed write circuitry.

Selection Guide

250 MHz

200 MHz

167 MHz

Unit

Maximum Operating Frequency

250

200

167

MHz

Maximum Operating Current

600

550

500

mA

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